Inserted blade cutter



y 1, 1934- F. P. MILLER ET AL 7,

INSERTED BLADE CUTTER Filed June 22. 1931 2 Sheets-Sheet 1 Qnwntoos FRANK P. MILLER' LE WIS SK E E L May 1, 1934. F. P. MILLER ET AL 1,957,348

' INSERTED BLADE CUTTER Filed June 22. 1931 2 Sheets-Sheet 2 wumtow FRANK P. MILLER LEWIS SKEEL.

Patented May 1, 1 934 PATENT,- OFFICE INSERTED BLADE CUTTER,

Frank P. Miller and Lewis Skcel, Mead'ville, Pa., assignors to McCrosky Tool Corporation, Meadville, Pa., a corporation of Pennsylvania Application June za osnsenai No. 540,000 '5 cm. (or -7e) This invention relates to cutting tools of the inserted blade type and has special reference to the blade holding means.

More particularly, the invention contemplates an inserted blade cutter in which the arrangement and structure of the parts thereof is such that the blade-holding screws, in addition to exerting effective lateral binding pressure on the blades, are caused to overhang portions of the blades to produce a compound locking action'by which the blades are held with certainty against shifting during use.

Further, the invention provides an inserted blade cutter in which the arrangement of the 5' locking means for the blades allows of the simple and expeditious adjustment of the blades to the desired cutting diameter and permits of the mounting and dismounting of the blades with facility.

Another feature of the invention resides in the provision of a cutting tool of the type alluded to which is of highly simplified construction, durable in use andcomparatively cheap to manufacture.

reamer the view illustrating the blade locking means in operative position, a

Figure 4 is a detail transverse sectional view through the reamer, the view illustrating the compound locking action by which the blades of the reamer are held in a securely locked position, Figure 5 is an end elevation of the locking screw, the view illustrating the eccentric form of the screw,

Figure 6 is a side elevation of the eccentric screw partly in section.

Figure 7 is a detail transverse sectional view illustrating a modification of theinvention, Figure 8 is an end view of the locking screw 3 shown in Figure 7; Figure 9 is a side elevation of the locking scre shown in Figures 7 and 8, a portion of the sam being in section.

Other objects and advantages will be apparent,

Figure 3 is a fragmentary plan view of a teamer,

screw and particularly the portion or section Figure 10 is a fragmentary group perspective of a boring bar embodying the invention.

Figure 11 is a fragmentary side elevation of the improved boring bar, the locking screw being shown in released position.

Figure 12 is a fragmentary side elevation of the boring bar, the locking screw being shown in operative position,

Figure 13 is a longitudinal sectional view through a portion of the boring bar shown in Figure 10,

Figure 14 is a fragmentary plan view illustrat-- ing another expression of the invention} Figure 15 is a detail transverse sectional view through the form of invention illustrated in Figure 1 Figure 16 is a fragmentary plan' view illustratanother form of the invention,

Figure 17 is a detail longitudinal sectional view through the rotary cutter disclosed in Figure 16.

In the drawings, and particularly Figures 1 to 6 inclusive, the numeral 20 generally designates a reamer body or head provided with an annular series of longitudinally extending slots 22 opening out through the periphery and forward end. thereof for the reception of blades 24. Figure 1 illustrates that thrust collars 26 may be threaded on the body at the rear ends of the blades to provide for adjustment of the blades and-at the same time to prevent rearward movement of the blades under the influence of the thrust thereon. However, as will become apparent, the invention is not restricted to use in connection with the particular type of reamer shown. Figure '1 illustrates that the body 20 is provided with sockets 28 extending transversely of the slots 22 and opening out through the periphery of the body 20 for the reception of eccentric binding screws 30. It is clearly illustrated that each socket 28 opens at one longitudinal side thereof into the associated slot 22 so that turning of the eccentric binding screw 30 will bring about effective lateral pressure contact between the eccentric 'screw and the associated blade, which lateral pressure contactacts in concert with an additional force to be described in locldng the blade firmly in place.

Referring now to Figure 5, it willbe seen that a portion of the circumference of the binding 32 is flat or is relieved so that when the same is in parallel relation to the adjacent side of the blade there will be no pressure contact between the screw and the blade. This, of course, allows the blade to be adjusted or removed. no

\ the blade. a

That portion of the circumference of the binding screw at one side of the fiat 32 is eccentric as indicated at 34 to define what mightproperly be said to be a locking cam for presentation to The remaining portion of the circumference of the screw is concentric as indicated at 36. It is believed to be clear that when the binding screw 30 has the flattened portion 32 thereof presented to the associated blade as shown in Figure 2, there is no lateral binding force exerted by the screw on theblade but, that when the screw is turned into the position shown in Figure 3,the eccentric portion 34 of the screw will be brought into effective lateral binding engagement with the blade to assist in holding the blade in place.

If the binding screw 30 is formed in the outer portionthereof with a polygonal socket as shown in Figures 1, 2 and 3, an L-shaped tool may be connected to the screw for adjustment purposes although it is clear that any other tool engaging means such, for example, as a screw driver slot may be formed in the outer end of the binding screw without departing from the spirit of the invention.

.Figure 4 illustrates that the screw 30 is extended at slight angle to the plane of the associated blade and that one side of the blade, and

more particularly the screw side thereof, is formed with a shallow groove 44 deepened gradually in the direction of the periphery of the reamer to define a screw engaging surface disposed substam tially parallel to the axis of the screw so that when the eccentric portion 34 of the screw is presented to the blade there will be uniform pressure contact between the screw and the blade for the major and, in fact, for almost the entire length of the screw.

disposition of the screw 30 and the wall of the groove 44 causes the screw to overhang the inner portion of the blade to the end that a compound wedging action is produced. That is to say, the screw is not only caused to exert an effective lateral pressure contact against the blade but at the same time overhangs the inner portion of the blade or, in effect, constricts the outer portion of the slot 22 so that the blade is held firmly in place.

In the use of the reamer shown in Figures 1 to 6 inclusive, the blades may be adjusted to the desired cutting diameter, and, of course, during such adjustmentthe binding screws 30 will occupy the released or inoperative positions shown in Figure 2. After adjustment of the blades the screws are turned to present the eccentric portions 34 of the screws to the blades and thereby exert a lateral binding force on the blades, which binding force, ascpreviously described, acts in concert with the overhanging of the. innerportions of the blades by the screws in effectively holding the blades in place.

In further alluding to the action of the binding screw, it is pointed out that turning of the same to bring about contact of the eccentric portion thereof with the blade urges the blade inward. In explaining this, attention is directed to the fact that the screw 30 is shown to have a left-hand thread with the result that when the screw is turned to bring about contact of the eccentric and threaded portion of the screw with the blade,

inward pressure as well as a lateral binding force will be exerted on the blade, thisbeing entirely separate from the restraininginfiuence brought about by disposing the screw at an angle to the screw with respect to the associated blade.

plane of the blade. Also, since the screw'is attached to the body 20 by screw threads, the accidental loss of the screw is much less likely than in the case of a plain or unthreaded binding element of eccentric form.

In the form of invention illustrated in Figures '7, 8 and 9 the screw 45 is of eccentric form and is provided with the flattened section as in the case of the screw shown in Figure 5 and differs from the screw shown in Figure 5 in that it is tapered toward the inner end thereof and has the axis thereof parallel to the plane of the blade. Thus, in comparing the constructions shown in Figure 4 on one hand and Figure '7 on-the other, it will be seen that the screw 30 shown in Figure 4 is at an angle to the plane of the associated blade while the screw 45 shown in Figure 7 is parallel to the plane of the associated blade. However, the screw 45 is caused to overhang the irmer portion of the associated blade 47 by reason of the taper of the eccentric portion of the screw. The blade 47 is shown to be provided at the screw side thereof with a groove or depression 49 gradually deepening toward the periphery of the body for the accommodation of the increased width "of the eccentric portion of the screw 45 toward the outer end thereof. v

As might otherwise be expressed, the wall of the groove 49 and the blade contacting surface of the screw 45 are disposed at an angle to the plane of 105 the associated blade to bring about an overhanging and consequently a restraining relation of the In this manner, a compound locking action is provided to hold the blade firmly in place.

It is shown in Figure '7 that the screw 45, like the screw 30, has left-hand screw threads urging the blade inward to firmly seated position. Now, it is important to observe that the angular Figures 10-14 inclusive illustrate the application of the invention in connection with a boring bar, the body of the latter being designated by the numeral 60, The body is formed with a transverse slot or opening 62 breaking out through opposite sides of the body and adapted for the reception of a pair of similarly formed blades 64.

It is clearly illustrated in Figure 13 that the blades 64 are increased somewhat in width toward the inner ends thereof to define angularly extending walls for contact by the eccentric binding screws 66.

A portion of the circumference of each binding screw 66 is formed with a longitudinal fiat 68. which when presented to the angularly disposed adjacent edge ofthe associated blade 64 allows the blade to be adjusted or removed. As shown in Figure 12, a portion of the circumference of the screw at one side of the longitudinal flat 68 is of eccentric form to define, in effect, 'a cam adapted for presentation to the adJacent edge of the blade to the end that the blade is locked firmly in place. That is to say, turning of the screw 60 will bring about pressure contact between the screw and the blade so that the blade is in turn forced flatly against the thrust-receiving rear wall of the slot 62. Of course, the threaded sockets for ,93 the reception of the screws 66 break for the full length thereof, into the transverse opening 62 to allow direct contact of the screws with the blades and in this connection it is noted that the eccentric portions of the screws are threaded, although 115' the outer edges of the threads on the eccentric portions of the screws are ground away and it is. this grindingaway that produces the eccentric formation of the screws. The partly mutilated threads on the eccentric portions of the screws 15c define a series of teeth that are, presented to the blades for binding engagement therewith.

In the construction of a boring bar embodying the invention, suitable means such as an adjusting screw '70 may be threaded into the body at right angles to the blades so that the tapered inner end of the adjusting screw may be engaged,

with the beveled inner ends of the blades. Ob-

' viously, advancement of the screw will bring tween the screws and the blades and this overhanging relation cooperates with the lateral binding force exerted on the blades by the screws in holding the blades in place. Thus, the blades are held in place by a compound wedging force. In further adverting to this important feature of the invention it is pointed out that the arrangement of the screws 66, in eifect, constricts the outer ends of the transverse opening 62 so that the outward movement of the blades is-not only restricted by the lateral binding force exerted by the screws, but by'the engagement of the screws with the slightly reduced outer ends of the blades.

It is believed to be clear that when the binding screws 66 have the fiats thereof presented to the blades, the blades may be withdrawn, since the width of the blades at the inner ends thereof is less than the distance between the thrustreceiving wall of the slot 62 and the flats of the screws. This is shown in Figure 11.

The binding screws 66 of the boring bar shown in Figures 10 to 13 inclusive, have right-hand threads so that when the screws are turned, the cam surfaces thereof are not only brought into effective lateral binding contact with the blades, but the blades are drawn inward thereby holding the blades more rigidly in place.

Coming now to the form of invention illustrated in Figures 14 and 15; the blade-holder of whatever nature the same happens to be, such, for example, as the head of a reamer, is formed with a slot 81 receiving a blade 82. Figure 15 illustrates that a binding screw 84, corresponding in general outline to a cap screw, is threaded into the body 80 at one side of the blade 82 in substantially parallel relation thereto and is formed with a head 86 for compound binding action against the associated blade.

In more specifically describing this feature, attention is'invited to Figure 14, in which it is illustrated that one side of the head 86 is provided with a flat corresponding to the fiat 32 shown in Figure 5, and at one side of this flat with an eccentric portion. As in the cases of the previously described structures, the eccentric portion constitutes a cam lock adapted for presentation to'the adjacent blade. It is clearly illustrated in Figure 15 that the eccentric portion of the head 86 extends at an angle to the axis of the binding screw 84 and to the plane of the blade so that the same is flatly engaged 'with periphery of the tool holder so that the bottom wall of this groove is disposed parallel to the eccentric, portion of the head 86 and in this manner flat and uniform pressure contact is provided between the head 86 and the blade.

-The gradual deepening of the groove 88 and the increased width of the head 86 toward the outer end of the latter causes the head to overhang a portion of the blade to wedge the blade firmly in place and thus there is an eifective compound wedging action by which shifting of the blade when finally adjusted is inhibited.

Figures 16 and 17 illustrate that'when the invention is carried out in connection with a rotary cutter such, for example, as a reamer, each eccentric, locking or binding screw 90 may be inclined toward the rear end of the associated blade 92 with the result that when the screw is turned to bring the eccentric portion thereof into binding engagement with the blade, the blade will be urged rearward and inward.

The arrangement of parts shown in Figures 16 and 17- contemplates left-hand threads for the screws so that when the screws are turned to lock the blades in place, the screws will at the same time be advanced, causing the blades to more firmly seat, this being in contrast to a righhand thread which would tend to unseat the blades. Thus, the arrangement shown in Figures 16 and 17 not only .holds the blades firmly in place by the compound locking action described in connection with the other forms of invention, but at the same time urges the blades rearward and inward to fully seated position and against the associated thrust collars or other stop means.

As indicated by the foregoing, a rotary cutter constructed in accordance with this invention is capable of a variety of mechanical expressions and the invention is capable of application to tools other than thoseillustrated. For example, the invention may be carried out in connection with milling tools and thus it is to be understood 1. In a cutting tool, a body having a slot, a.

blade in the slot and having a contact wall disposed at an angle to the longitudinal medial plane of the blade and a longitudinally tapered screw threaded into the body contiguous to and parallel to the blade. and having an excentric peripheral portion for presentation to the contact side wall of said blade upon rotation of said screw to clamp said blade in position;

2. In a cutting tool, a body having a slot, a blade in the slot and having a contact surface disposed at an angle to the longitudinal medial plane of the blade and a binding screw threaded into the body and being contiguous to and par allel to said blade and having an eccentric side wall adapted upon rotation of said screw to engage the angularly disposed contact surface of the blade to clamp said blade in position, said screw being uniformly increased in diameter from a point adjacent to the inner .end thereof to the outer end thereof to cause the screw to overhang a portion of the blade to produce a compound wedging action holding the blade against shifting.

slot, a blade in the slot and having leading and trailing sides, the leading side being provided with a screw contact surface converging in the -8directionoftheoutersurfaceo!thecuttertcward thetrailingside ofthe blade,ascrew thread- 'edintosaidbodytelyatrightangles to the blade and having one longitudinal side thereof of eccentric form for lateral wedging contact with said screw contact surface, the longitudinalaxisofsaidscrewbeingsubstantiallyparallel to the leading side of the blade with the crosssectionalareaofthescrewtoward the outer end thereof to cause the screw to have overhanging relation to the blade increased toward the outer end of the screw producing a com-. pound wedging action.

4. Inaninsertedbladecuttenabowhavinga slot, a'blad in the slot and having leading and trailing sides, the leading side being provided with a screw contact surface in converging relation to the trailing side of the blade-in the direction of the outer edge of the blade, a screw threaded into said'body at right angles to the lengthofthebladeandhavingcneiongitudinal side thereof of eccentric form for lateral wedging contact with saidscrewcontact surface,thescrew having the longitudinal axis thereof approaching thebladeinthedirectionoftheouteredgeofthe bladeatanacuteangletothebladewherebvthe screw is caused to havean overhanging relation tothebladeincreasedtowardtheouterendofthe screw producing a compound wedging action section for lateral t' with said" screw contact surface, said eccentric portion of thescrewhavingoverhangingrelationtothe bladevelyinthedirectionof' therearendotthescrewandtheperipheryofthe body, the threads of said screw and said socket being left-handed to urge the blade inward.

La-ms manxnmmm. 

